Mammary gland of female rats is the most common site of tumor induction by a variety of chemical compounds. However, information on the capacity of the mammary gland to metabolize foreign compounds including mammary carcinogens is scarce. In this proposal we shall investigate whether activation of N-2-fluorenylacetamide (2-FAA) to the N-hydroxy compound is inducible in the mammary gland by treatment of lactating rats with 2-FAA, a known inducer of hepatic microsomal N-hydroxylation. We shall also investigate whether carcinogenic metabolites of 2-FAA produced in the liver are transported to the mammary gland and excreted in the milk of lactating rats. We shall determine metabolite profile in the milk by high pressure liquid chromatography (HPLC) and quantitate free and protein-bound metabolites. Furthermore, we shall examine carcinogenicity of the milk of 2-FAA-treated lactating rats for the suckling young of both sexes. We also propose to investigate two mechanisms by which electrophilic reactants, presumably required for carcinogenesis, could be generated from arylhydroxamic acids in the mammary gland: 1. Formation of O-glucuronides of fluorenylhydroxamic acids. An HPLC method for detection and quantitation of these conjugates will be developed. Possible hydrolysis of O-glucuronides of fluorenylhydroxamic acids by the mammary gland beta-glucuronidase will also be investigated and the products of hydrolysis, i.e., fluorenylhydroxamic acids, measured by the HPLC method. 2. One-electron oxidation of fluorenylhydroxamic acids to nitroxyl radicals. This possibility will be examined by electron spin resonance (ESR) spectroscopy and HPLC. Reactivity of the nitroxyl radicals with exogenous DNA and protein as well as with endogenous (mammary cell) macromolecules will be investigated.